20. What is the molecular formula for alkane, alkenes and alkynes?
15.What happens to a reaction at equilibrium when more reactant is added to the system?
For questions like this you should tell us what you think or at least something about what you don't understand about the question.
Alkanes are CnH(2n+2)
alkenes are CnH2n
alkynes are CnHn
In a reaction, for example,
A + B --> C + D
If more A is added or if more B is added the equilibrium shifts to the right.